Gabriela (shortened to Iela) studied painting at Milan's Brera Academy, where she met her future husband, Enzo Mari, who was pursuing scenography at the time.

Mari's main idea was to use shapes and colors in an almost abstract way: the author was convinced that the thought of young children, to whom her work was addressed, proceeded by associations, and that this could allow them to develop selective attention while simultaneously stimulating their imaginations.

"[2] In 1968 with the publication of her first book, The Red Balloon, she said: "I would like to draw attention to the forms in relation to the bombardment of the images produced by television.

[3]Her books continue to be published around the world, including France, England, Spain, Portugal, Germany, Japan, Taiwan and Korea.

Iela Mari twice received awards from the Bologna Children's Book Fair (Italy): in 1973 for L'Albero (The Tree, the Dormouse and the Birds), and again in 1977 for Once Upon a Time There was a Sea Urchin.